1. Statement of the Technical Field
The inventive arrangements relate to switches, such as broad-band, low-loss radio frequency (RF) microelectromechanical systems (MEMS) switches.
2. Description of Related Art
Communications systems, such as broadband satellite communications systems, commonly operate at anywhere from 300 MHz (UHF band) to 300 GHz (mm-wave band). Such examples include TV broadcasting (UHF band), land mobile (UHF band), global positioning systems (GPS) (UHF band), meteorological (C band), and satellite TV (SHF band). Most of these bands are open to mobile and fixed satellite communications. Higher frequency bands typically come with larger bandwidths, which yield higher data rate operation. Switching devices used in these types of systems need to operate with relatively low losses, e.g., less than one decibel (dB) of insertion loss, at these ultra-high frequencies.
Miniaturized switches such as monolithic microwave integrated circuit (MMIC) and MEMS switches are commonly used in broadband communications systems due to stringent constraints imposed on the components of such systems, particularly in satellite-based applications. Currently, the best in class switches operate at 40 GHz with culumative attributes such as insertion losses of approximately 0.6 dB, return losses of approximately 13 dB, and isolation levels of approximately 40 dB.
Three-dimensional microstructures can be formed by utilizing sequential build processes. For example, U.S. Pat. Nos. 7,012,489 and 7,898,356 describe methods for fabricating coaxial waveguide microstructures. These processes provide an alternative to traditional thin film technology, but also present new design challenges pertaining to their effective utilization for advantageous implementation of various devices such as miniaturized switches.